New planet discovered in 2010 lies in Goldilocks zone for life

A new planet was discovered in 2010 orbiting the star Gliese 581 at a distance called the Goldilocks zone, where conditions are just right to support life. Image: CC richardmasoner/Flickr

A new planet, or exoplanet, has been discovered in 2010 that may support life. For 11 years, planet hunters have been monitoring a red dwarf star called Gliese 581 about 20 light years away suspected of harboring an Earthlike planet. Wednesday they announced the discovery of Gliese 581g, a rocky planet orbiting its star in the “Goldilocks zone,” a distance considered “just right” for water to exist for the development of organic life.

Welcome to the Goldilocks zone

The new planet discovered in 2010, Gliese 581g, was announced by Steven S. Vogt of the University of California, Santa Cruz and R. Paul Butler of the Carnegie Institution of Washington. As reported in the New York Times, Gliese (GLEE-za) 581g orbits Gliese 581, a dim red star, once every 37 days at a distance of about 14 million miles. Scientists say that is the sweet spot of the Goldilocks zone, where heat from the star is not too hot, not too cold, for water to exist in liquid form on the surface. When asked about life on Gliese 581g, Vogt said the chances “are almost 100 percent.”

Why Gliese 581g may support life

Gliese 581g is one of six known planets orbiting Gliese 581, a star about one-third the size and one-hundredth the brightness of the sun. Scientific Americans reports that two of the Gliese 581 planets bracket the Goldilocks zone. Gliese 581g, about three times the mass of Earth, orbits between those. It is the first Goldilocks exoplanet to be discovered. But it’s not exactly Earthlike. The planet hunters suspect Gliese 581g is “tidally locked,” which means only one side faces its star. Surface temperatures are expected to range from 31 below zero at night to 158 degrees in the day. Somewhere in between permanent daylight and permanent night, which Vogt called “eco-longitudes,” some form of life could become established.

How new planets are discovered in 2010

Gliese 581g was discovered using the radial-velocity, or “wobble,” technique. As explained in the Los Angeles Times, the wobble technique detects planets by measuring a barely discernible gravitational tug they give their star during orbit. The planet hunters also made precise brightness measurements, confirming that the specific wobbles in Gliese 581 were triggered by Gliese 581g, not by any activity within the star itself.